1. Field of the Invention
The present invention relates to a control device for a washing machine wherein a transmissivity sensing device having a luminous element and light sensing element and serves to sense how foul the washing water is.
2. Description of the Related Art
A normal control device for a washing machine is designed to provide a foul sensing device, in a drain path of the washing machine. Using a transmission sensing device, the foul sensing device serves to sense the degree of light that is transmitted through the water in a washing bath for controlling functions of the washing machine such as washing and rinsing. In such a control device, there has been proposed a method for checking the transmission sensor as disclosed in JP-A-61-213094. This method is designed to sense and display how much an optical axis of a luminous element has moved away from that of a light sensing element or how foul their elements are, based on the sensed light transmission in the manufacturing process. The method thus makes it easy to test the product.
The main object of the method disclosed in JP-A-61-213094 is to check for defective light transmission in the manufacturing process. This method, therefore, needs troublesome techniques for manipulation under the special condition of the domestically-used washing machine.